Prevously, if we hotplug a device(e.g. device_add e1000) during
migration is processing in source side, qemu will add a new ram
block but migration_bitmap is not extended.
In this case, migration_bitmap will overflow and lead qemu abort
unexpectedly.
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
---
exec.c | 7 ++++++-
include/exec/exec-all.h | 1 +
migration/ram.c | 16 ++++++++++++++++
3 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/exec.c b/exec.c
index f7883d2..04d5c05 100644
--- a/exec.c
+++ b/exec.c
@@ -1401,6 +1401,11 @@ static ram_addr_t ram_block_add(RAMBlock *new_block,
Error **errp)
}
}
+ new_ram_size = MAX(old_ram_size,
+ (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS);
+ if (new_ram_size > old_ram_size) {
+ migration_bitmap_extend(old_ram_size, new_ram_size);
+ }
/* Keep the list sorted from biggest to smallest block. Unlike QTAILQ,
* QLIST (which has an RCU-friendly variant) does not have insertion at
* tail, so save the last element in last_block.
@@ -1435,7 +1440,7 @@ static ram_addr_t ram_block_add(RAMBlock *new_block,
Error **errp)
ram_list.dirty_memory[i] =
bitmap_zero_extend(ram_list.dirty_memory[i],
old_ram_size, new_ram_size);
- }
+ }
}
cpu_physical_memory_set_dirty_range(new_block->offset,
new_block->used_length,
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index 2573e8c..dd9be44 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -385,4 +385,5 @@ static inline bool cpu_can_do_io(CPUState *cpu)
return cpu->can_do_io != 0;
}
+void migration_bitmap_extend(ram_addr_t old, ram_addr_t new);
#endif
diff --git a/migration/ram.c b/migration/ram.c
index 4754aa9..70dd8da 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1063,6 +1063,22 @@ static void reset_ram_globals(void)
#define MAX_WAIT 50 /* ms, half buffered_file limit */
+void migration_bitmap_extend(ram_addr_t old, ram_addr_t new)
+{
+ qemu_mutex_lock(&migration_bitmap_mutex);
+ if (migration_bitmap) {
+ unsigned long *old_bitmap = migration_bitmap, *bitmap;
+ bitmap = bitmap_new(new);
+ bitmap_set(bitmap, old, new - old);
+ memcpy(bitmap, old_bitmap,
+ BITS_TO_LONGS(old) * sizeof(unsigned long));
+ atomic_rcu_set(&migration_bitmap, bitmap);
+ migration_dirty_pages += new - old;
+ synchronize_rcu();
+ g_free(old_bitmap);
+ }
+ qemu_mutex_unlock(&migration_bitmap_mutex);
+}
/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
--
2.1.4
